Specialty testing & calibration glossary

An independent organization, such as A2LA or ANAB in the US, that assesses and formally recognizes a laboratory's competence to perform specific tests or calibrations, typically against the ISO/IEC 17025 standard.

Related: ISO/IEC 17025, Scope of accreditation

See: astm accredited testing lab buyers guide

Also: ISO 17025

The general international standard for the competence of testing and calibration laboratories, covering both management-system requirements (like ISO 9001) and technical requirements specific to producing valid test and calibration results, including measurement uncertainty and proficiency testing.

Related: Scope of accreditation, Accreditation body, Proficiency testing

See: astm accredited testing lab buyers guide

Also: PT, round-robin testing

A quality-assurance process in which a laboratory analyzes blind samples, often distributed by an independent provider, and its results are compared against a reference value or other participating labs, used to verify ongoing competence and required for maintaining ISO/IEC 17025 accreditation.

Related: ISO/IEC 17025, Accreditation body

See: astm accredited testing lab buyers guide

Also: accredited scope

The specific, itemized list of test methods, standards, product or material classes, or (for calibration) measurement parameters and ranges a laboratory is actually accredited to perform, as distinct from the accreditation certificate itself, which is often a general summary document.

Related: ISO/IEC 17025, Accreditation body

See: astm accredited testing lab buyers guide, how to choose a materials testing laboratory

A document issued after an instrument is calibrated, stating the measured values, the reference standards used, the measurement uncertainty, and the traceability chain back to a national measurement standard.

Related: Traceability (metrology), Measurement uncertainty

See: astm accredited testing lab buyers guide

A quantified estimate of the range within which the true value of a measurement is expected to lie, reported alongside a calibration or test result to describe how much confidence to place in it.

Related: Traceability (metrology), Calibration certificate

See: astm accredited testing lab buyers guide

Also: metrological traceability

An unbroken chain of calibrations connecting a measurement result back to a national or international measurement standard (such as those maintained by NIST in the US), with each link in the chain carrying its own stated measurement uncertainty.

Related: Measurement uncertainty, Calibration certificate

See: astm accredited testing lab buyers guide

The maximum allowable time between sample collection and laboratory analysis for a given method, after which a regulatory result may be considered invalid because the analyte could have degraded or changed.

Related: Chain of custody

See: how to choose an environmental testing lab

Also: LOQ

The lowest concentration of an analyte that can be measured by a given method with acceptable accuracy and precision, typically a higher concentration than the method detection limit.

Related: Method detection limit (MDL)

See: how to choose a chemical testing lab

Also: MDL

The lowest concentration of an analyte a specific analytical method can reliably distinguish from a blank or background signal with a stated statistical confidence.

Related: Limit of quantification (LOQ), PFAS

See: how to choose an environmental testing lab, how to choose a chemical testing lab

Also: PFAS, forever chemicals

A large group of synthetic chemicals increasingly regulated in drinking water, soil, and consumer products, commonly tested for in environmental and chemical testing labs using methods such as EPA Method 537.1 or 533.

Related: Method detection limit (MDL)

See: how to choose an environmental testing lab, how to choose a chemical testing lab

A test method that permanently damages, alters, or consumes the sample being tested, such as tensile testing to failure or sectioning a part for metallography, as opposed to non-destructive testing.

Related: Non-destructive testing (NDT), Tensile testing

See: how to choose a materials testing laboratory

A mechanical test that measures a material's resistance to localized plastic deformation, commonly performed using the Rockwell, Brinell, or Vickers scales.

Related: Tensile testing, Metallography

See: how to choose a materials testing laboratory

The microscopic examination of a metal's polished and etched surface to study its internal grain structure, phase composition, and any manufacturing or in-service defects.

Related: Fractography, Hardness testing

See: how to choose a materials testing laboratory, failure analysis laboratory buyers guide

Also: salt fog testing

An accelerated corrosion test in which a sample is exposed to a controlled saline mist inside a test chamber to evaluate a coating's or material's corrosion resistance over a defined exposure period.

Related: Tensile testing

See: how to choose a materials testing laboratory

A mechanical destructive test that pulls a material sample until it breaks, measuring properties such as yield strength, ultimate tensile strength, and elongation at failure.

Related: Hardness testing, Destructive testing

See: how to choose a materials testing laboratory

The study of a fracture surface, typically under magnification such as a scanning electron microscope, to determine the mechanism and point of origin of a material failure.

Related: Root cause analysis (failure analysis), Metallography

See: failure analysis laboratory buyers guide

Also: NDT

A group of inspection methods, including ultrasonic, radiographic, magnetic particle, dye penetrant, and eddy current testing, that examine a material or component for internal or surface flaws without damaging or altering it.

Related: Destructive testing, Fractography

See: ndt testing services buyers guide

Also: root cause failure analysis

A systematic investigation process used to identify the underlying mechanism that caused a component or material to fail, rather than merely describing the visible damage.

Related: Fractography

See: failure analysis laboratory buyers guide

The documented, unbroken record of who collected, handled, transported, and analyzed a sample, used to establish the sample's integrity for regulatory, legal, or accreditation purposes.

Related: Holding time

See: how to choose an environmental testing lab, what is a third party testing lab

Also: first party testing, second party testing, third party testing

A classification of who performs a test relative to the party with an interest in the outcome: first-party is the manufacturer's own internal lab, second-party is a buyer's or customer's own lab testing a supplier's goods, and third-party is an independent lab with no ownership stake in either side.

Related: Chain of custody

See: what is a third party testing lab

Also: NRTL

A status the US Occupational Safety and Health Administration (OSHA) grants to specific testing labs, authorizing them to test and certify certain product categories against safety standards for workplace and electrical-code compliance.

See: how to choose a product testing laboratory